The invention relates to a sewing needle for a sewing machine, wherein said needle may thus also be referred to as a machine sewing needle. The sewing needle comprises a needle body that has, on its one end, a holding portion for clamping the sewing needle into a corresponding holding arrangement of the sewing machine. On the side opposite the holding portion, the needle body has a working portion that terminates in the needle tip. In this working portion of the needle body, there is also provided a needle eye which extends completely through the needle body and through which the upper thread passes during the sewing operation.
Frequently, sewing needles are manufactured with the use of a stamping process. In doing so, frequently a recess is formed adjoining the needle eye in the direction of the longitudinal axis, said recess being referred to as the tip groove. This tip groove also exists in document EP 1 127 973 B1 and is designed so as to be deeper opposite the two lateral walls of the needle eye, so that the sewing thread slides over a flank or edge between the tip groove and the lateral wall of the needle eye when the sewing direction is changed. As a result of this, a twist shifting of the sewing thread may occur.
A sewing needle for multi-directional sewing has been known from document EP 1 127 973 B1. The sewing needle has an elongated needle eye that extends through the needle body and is delimited by two opposing lateral walls. The needle body extends along a longitudinal axis. In order to spare the thread guided during the needle eye during the sewing operation, the two lateral walls are curved in a concave manner on their lateral wall edges—viewed in the direction of the longitudinal axis. When the thread exits in an oblique manner or laterally from the needle eye, it will be guided over one of the two concavely lowered lateral walls of the needle eye. Due to this measure a twist shifting of the sewing thread is to be avoided. While the thread is moving over the lateral wall, the twisting effect of the sewing thread should only be minimally changed or not changed, as a result of which sewing errors are avoided and a thread is spared.
Document DE 10 2009 004 033 A1 describes a sewing needle for a sewing machine that has a groove extending in the direction of the longitudinal axis in the needle body on the side opposite the needle tip, said groove terminating in the needle eye. At one point before the termination of the groove in the needle eye, said groove has a portion that is angled relative to the longitudinal axis of the needle body. Due to this angled groove, the compressive force acting on the sewing thread in the region of the needle eye is intended to be oriented in the direction of the tilt of the sewing thread in order achieve the untwisting of the sewing thread.
Document DE 86 32 106 U1 describes a tufting needle in which the needle tip is offset relative to the needle axis in transport direction of the backing. This is to prevent that when the backing of the previously laid thread is punctured and thus damaged due to the oscillations of the tufting needle. The tufting needle may also have a thread groove that extends in an oblique manner starting from the needle eye—in a manner so as to be inclined relative to the longitudinal axis of the needle—and ends above the needle tip. As a result of this, the thread is to be deflected from the longitudinal axis of the needle where the needle tip is located.
The needle described in document GB 703 934 A is designed specifically for use when sewing a shoe. The needle is designed without a needle eye and has in the needle body in a working portion a recess, as a result of which a hook-like projection is formed. The needle is punctured through the material to be sewn. With this projection it is possible to grasp a thread loop—similar to crocheting—and to pull it on the other side of the sewn material. Thus, this needle is specifically configured to perform a sewing stitch type 101 compliant with DIN 614:2002-04.